1. Field of the Invention
The present invention relates to a self-propelled windrow merger apparatus and a method of merging windrows. In particular, the present invention relates to a self-propelled windrow merging apparatus and method having more than two head and conveyor assemblies that form a continuous path in use and retract for transport.
2. Description of the Prior Art
Devices for merging windrows are well known and are used to gather material, such as cut hay that might be windrowed, and merge it into a single windrow for harvesting or baling. Such windrow mergers typically included a single pickup head to move the material to a single row at one side of the merger. When used on a relatively small scale, these devices generally function in a satisfactory manner. However, for large scale operations requiring merging on large fields, the capacity of such mergers is limited because of their width and may not be sufficient to merge the material at an adequate rate for subsequent pickup by other devices. The merging must often be performed during a small timeframe when conditions are favorable so that the need exists for a merger with greater merging capacity so as not to slow the harvest process. A limiting factor for the size of the merger device has been the towing capacity and availability of tractors and other propulsion devices and the width of the merger devices during transport. The machines must be transported from field to field and must be able to accomplish entry and exit in and out of fields, as well as meeting width limitations for transport on public highways and other roads without removing the heads.
In order to achieve a wider merger apparatus, folding mergers have been developed, such as shown in U.S. Pat. No. 6,205,757 to Dow et al The Dow et al. '757 patent has a two headed merger device that folds to a storage position for transport. In addition, the Dow device utilizes transverse conveyors to move materially laterally and provide various configurations for moving material to the desired windrow. The Dow et al. '757 patent teaches a device that is successful in providing higher capacity, greater width, and improved methods of merging while folding to a storage position for transport. However, further improvements to windrow mergers are possible.
Utilizing wider folding heads provides design challenges, especially achieving a linkage for folding wide heads and providing acceptable support, while limiting the loads and torque in operating positions, storage positions and during movement between the use position and the transport position. In order to achieve higher capacity, the heads may be widened, but the design becomes more complicated and difficult due to moving wider heads and staying within height and width limitations when folded. Controls and mechanisms for folding more than two heads are not contemplated in the prior art.
Moreover, another problem that devices having multiple heads suffer from is that they typically form a gap between the ends of adjacent pickup heads so that some material may be missed in the field as the merger advances. Motors and other drive equipment have typically been positioned at ends of heads, providing an obstruction between the ends of the heads, requiring a gap between the end rows of tines adjacent the heads. Operating prior adjustable conveyors at a sufficient rate so that material is passed from one conveyor to the other has required spacing that allows for adjustment, which prohibits an unobstructed pickup face without gaps. Achieving a conveyor that does not require adjustable end rollers would improve the liability and eliminate constant adjustment for different configurations. If such manual adjustment is not required, control of the merger apparatus and changing between different operating configurations, or changing between storage and use positions could be accomplished remotely by an operator of the towing vehicle without having to manually adjust conveyor heads and other equipment. The utility of such a merger apparatus is increased if such changes and configurations may be made during merging without having to stop.
For some applications, a tractor is not available to tow the larger mergers, especially during the short windows available during harvest when the tractor may be needed for other tasks. In addition, tow behind mergers require the operator to be driving a tractor while monitoring the merging operation behind the tractor. Operations are easier if the merger heads are in front of the operator in use. Moreover, a self-propelled merger has greater utility if the heads can be retracted to a narrower configuration for transport and with the end heads behind the cab during transport so as not to create a large blind spot. A tractor and coupled merger combination may be difficult to maneuver in corners or smaller spaces or when entering or leaving fields.
It can be seen that a new and improved self-propelled windrow merging apparatus is needed. A self-propelled merger should have a pickup face in front of the operator so that the operator may look forward and view the heads picking up material. Such a merger should provide for a wider effective pickup face that can accommodate various spacing of windrows and material and an unobstructed pickup face so that material is not missed in the field. Such a merger apparatus should provide for a merger having more than two heads and allow for folding of the heads between a use position and a retracted transport position, allowing for transport on public roads. A merger should utilize a simple pivot arm to move the pickup and conveyor assemblies between a use position and retracted position. The present invention addresses these as well as other problems associated with windrow merging devices and merging operations.